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Abstract:

The present invention relates to a platform (12) for carrying and
transporting loads, with a frame (16), with a chassis (20) at the front
end of the platform (12), by means of which the platform (12) is
moveable, with a revolving belt (26) which is guided on a closed, endless
track in the frame (16) and with a bell drive (40) for the revolving belt
(26), wherein the chassis (20) can be retracted and extended in order to
lower and raise the front end of the platform (12). In addition, the
present invention relates to a transport device (10) with a platform (12)
of the abovementioned type and a transport vehicle (14) which can be
coupled thereto.

Claims:

1. A transport device (10) comprisinga platform (12) for carrying and
transporting loads comprising a frame (16);a chassis (20) at the front
end of the platform (12) by means of which the platform (12) can be
moved;a circulating belt (26) guided on a closed, endless track in the
frame (16), and a belt drive (40) for the circulating belt (26);wherein
the chassis (20) is retractable and extendable in order to lower and
raise the front end of the platform (12); anda transport vehicle (14)
couplable thereto which comprises one or a plurality of steerable drive
rollers (90) and one or a plurality of free-wheel supporting wheels (42)
which can alternatively function as freely-moveable steering rollers or
can be locked in the straight-ahead position.

2. The transport device according to claim 1, wherein the chassis (20) is
pretensioned in an extended state so that the chassis (20) will retract
upon load.

3. The transport device according to claim 1, further comprising a
coupling disposed on a rear end of the platform (12) for coupling a
transport vehicle (14) thereto, the coupling substantially rigid relative
to a vertical axis.

4. The transport device according to claim 3, wherein the coupling is
tiltable about a horizontal axis (88).

5. The transport device according to claim 1, wherein a drive mechanism
(46) of the belt drive (40) for the circulating belt (26) and a control
for same are arranged in the transport vehicle (14).

6. The transport device according to claim 1, wherein the extending and
the retracting of the chassis (20) is controllable from the transport
vehicle (14).

7. The transport device according to claim 1 wherein the platform (12)
comprises at least one length adjusting element (56;58) for adapting a
longitudinal extension of the platform (12) and in particular for
adapting an elongation of the circulating belt (26).

8. The transport device according to claim 7, wherein the length adjusting
element (56;58) is arranged between two adjacent platform base sections
(148;148').

9. The transport device according to claim 7, wherein the length adjusting
element (56;58) is an eccentric (56) or an opposing-splined wedge strip
(58).

Description:

[0001]The present invention relates to a platform for carrying and
transporting loads comprising a frame, a chassis at the front end of the
platform by means of which the platform can be moved, a circulating belt
guided on a closed, endless track in the frame, and a belt drive for the
circulating belt.

[0002]The invention further relates to a transport device having a
platform of this type and a transport vehicle which can be coupled to
said platform.

[0003]Because the circulating belt of the platform is guided on a closed,
endless track; i.e. the base of the platform can roll, even heavier
machines or order-picked goods can be unloaded by pulling the platform
away from under the machine or order-picked goods. A transport vehicle
additionally transports the loaded platform to its intended positional
location. When at said location, the transport vehicle pulls the platform
backwards. The belt drive can drive the roll-off base in the opposite
direction to the direction of the platform's travel such that when the
platform is being backed up, the movement of the platform is converted
into an oppositely-directed roll-off motion of the rolling base at a 1:1
ration and the machine or other load cannot change its position relative
the ground surface below upon the withdrawing of the platform and can be
precisely positioned. The machine, the order-picked goods or other load
thereby slowly slides forward on the rolling base off the platform.

[0004]A transport device having a platform for transporting and efficient
unloading of material is known from U.S. Pat. No. 2,432,182. The base of
the platform is formed by a plurality of rollers which extend almost the
entire width of the platform and are held in a rectangular frame. The
platform rests on lateral rails so that a transport vehicle in the form
of a forklift can drive under the platform and lift it up. A forklift is
used, the fork arms of which are equipped with a corresponding plurality
of rollers. The rollers of the platform and of the forklift all have the
same diameter and are arranged in the same pattern such that the rollers
of the platform respectively position between two of the forklift
rollers, thereby coupling the forklift to the platform. The forklift sets
the platform down at an unloading point and drives backwards. The rollers
of the forklift thereby roll back along the surface and transfer their
rotational motion to the platform rollers so that the load on the
platform rolls off from the platform. This roll-off movement is thereby
the polar opposite to the backward motion of the forklift and the
platform such that the load is kept in position relative the ground
surface underneath it while it rolls off from the platform.

[0005]In a platform of the type indicated above known from WO 2000/039000,
a gear or a drive chain drives the roll-off base via one or more friction
rollers which can be configured as rigid heavy-duty rollers. A free-wheel
and a clutch are disposed between the one or more friction rollers and
the roll-off base. In order to be able to set the load down on the ground
as smoothly as possible, a ramp is provided on the front and rear end of
the platform to bridge the difference in height at that point and enable
setting down the load without jolting it.

[0006]The present invention is based on the task of providing a platform
with a roll-off base which will enable a load carried on the platform to
be set down or unloaded with as little jarring as possible and precisely
at a predetermined position.

[0007]The task is solved in accordance with the invention by a chassis
being able to be extended and retracted in order to lower and raise the
front end of the platform.

[0008]The chassis is preferably arranged as far forward as possible at the
front end of the platform. This allows the platform to maneuver easily,
also in the case of a relatively large surface area of e.g. 2.4×2.4
m, corresponding to the surface area of six standard transport pallets of
0.8×1.2 in.

[0009]The chassis is preferably pretensioned in the extended state so that
it will retract upon load.

[0010]By the retracting of the front chassis, the platform is lowered
almost completely to the ground surface on which to unload so that the
load can be set down on the ground with virtually no jarring. A longer
gravity incline is generally not necessary on the platform in order to
enable the load to be set down jolt-free. This is advantageous because
ramps are an obstacle to jolt-free loading and make maneuvering the
platform more difficult. The outer dimensions of the platform also have
to be larger and neither does a ramp constitute a usable part of the
platform's surface area. A narrow bar or knife edge is however advisable
on the front end of the platform to protect the circulating belt.

[0011]The belt drive can be integrated into the platform. An electric
motor or a piston engine can thus be provided which is controlled by a
positional sensor and drives the circulating belt opposite to the
distance covered.

[0012]Preferably, however, a transport vehicle can be coupled to the rear
end of the platform in fixed coupling to the vertical axis. This coupling
is functionally tiltable about a horizontal axis is order to be able to
adjust to ground surface irregularities.

[0013]The belt drive for the circulating belt or the roll-off base and the
control for same are preferably arranged in the transport vehicle.

[0014]Generally speaking, the platform has a rectangular frame comprising
two or more longitudinal bars connected by crossbars. The chassis, which
is at the front end of the platform, can be integrated in the
longitudinal bars and is retracted into the hollow space of said
longitudinal bars upon the lowering of the platform.

[0015]An actuating mechanism for the chassis is provided to extend and
retract it. The actuating mechanism can comprise an actuating cylinder or
a spindle drive which acts on the chassis mechanism via a push/pull rod.
The entire actuating mechanism can likewise be integrated into the
platform. Preferably, however, the actuating cylinder is disposed on the
transport vehicle while the push/pull rod runs through a longitudinal bar
of the platform. The piston of the actuating cylinder or the spindle
drive, aligning with the push/pull rod upon the coupling of the platform
to the transport vehicle, couples to the end of the push/pull rod. Thus,
also the extending and retracting motion of the chassis is preferably
controllable from the transport vehicle.

[0016]Close to the front end of a longitudinal bar of the platform, the
chassis can exhibit a double-arm angle lever pivotably mounted at the
point of intersection of the two arms about an axis extending
horizontally transverse to the direction of travel. The two angular arms
form an angle of approximately 80 degrees. The longer angular arm points
forward, with a pivotably-mounted single, double or tandem roller or an
apron conveyor arranged at its free end. The push/pull rod acted upon by
the actuating cylinder is articulated at the end of the shorter arm
pointing rearward.

[0017]The chassis has one or more rollers depending on the platform's
intended load capacity or, for very high loads and/or very uneven ground
surface, an apron conveyor in place of the rollers. Tandem rollers are
preferably utilized to realize a lower overall height. Two single or
tandem rollers are generally sufficient up to a load capacity of
approximately 2000 kg. When the platform is to have a greater load, an
accordingly greater number of rollers can be provided. The maximum load
is theoretically limited here by the properties and condition of the
ground close to the chassis. The chassis rollers at the front end of the
platform are generally not steerable.

[0018]The transport platform, its maximum load respectively, is generally
determined by the nature of a freight truck and its loading platform. In
this respect, it is advantageous to install profiled rails on the freight
truck, its loading area respectively, or at another appropriate storage
location for the transport platform removed from the transport platform
chassis. This thus enables the transport rails to be either firmly
attached to the loading area, etc., or also detachably attached to the
transport platform so they can be laid out as needed.

[0019]The actuating mechanism for the chassis is preferably constructed
such that the chassis is extended when not in operation. It is further
preferred for the actuating mechanism to be designed such that the
chassis retracts upon the platform being loaded and the platform lowers.
This can be realized by a spring mechanism pretensioning the push/pull
rod in the extended state of the chassis. To mechanically retract the
chassis, the piston of the actuating cylinder or spindle drive pushes the
push/pull rod forward, thereupon overcoming or neutralizing the initial
tension. The pretensioning of the chassis in the extended state and the
automatic retraction upon a given load on the platform guards against the
platform being overloaded.

[0020]The pretensioning can be generated by a pressure spring arranged on
the push/pull rod which braces against a stop inside the longitudinal bar
and a stop on the push/pull rod. The rear end of the push/pull rod is
situated in an opening at the rear end of the platform's longitudinal
bar. When coupling the transport vehicle, it hereby suffices for the end
of the push/pull rod to align with and in front of the piston of the
actuating cylinder arranged on the transport vehicle, since the piston
only needs to act to retract the push/pull rod; extending of the chassis
is effected by the pretensioning when the piston pulls back.

[0021]There are two possible ways to lower the platform and retract the
chassis:

[0022]The first possibility entails--as noted above--keeping the chassis
extended by the push/pull rod via a pre-loaded spring. To retract, the
piston of the actuating cylinder or the spindle drive butting the end of
the push/pull rod pushes on the push/pull rod and supercompresses the
preloaded spring of the chassis such that the chassis retracts and the
platform lowers. To extend the chassis, the piston gives way so that the
tensioning of the push/pull rod pushes the piston backward. Utilizing the
pre-loaded spring also yields protection against overloading: when
overloaded, the chassis retracts.

[0023]In the second possibility, the chassis is kept in its position by a
locked push/pull rod. Tensioning is not provided. To lower, the locking
disengages, the piston rod of the actuating cylinder gives way, and the
chassis lowers accordingly. Lifting ensues in reversed order.

[0024]When unloading, the chassis at the front end of the platform is
retracted so that the front edge of the platform comes into full or
almost full contact with the ground and the load thus moves along a
uniformly inclined plane at a substantially unvarying inclination and can
ultimately be set down on the ground surface.

[0025]The rolling base or the circulating belt is preferably designed as a
modular link conveyor. Said modular link conveyor consists of a plurality
of chain links, each exhibiting two series of grommets respectively
connected to the corresponding series of grommets of the adjacent chain
link by means of a connector pin. The upper side of the modular link
conveyor is even while the interconnected series of grommets form ribs on
the underside.

[0026]The upper side of the frame is formed by a substantially closed
sliding plate, the modular link conveyor lying atop said sliding plate.
The material of the sliding plate is selected such that the combination
of materials it produces with the material of the modular link conveyor
has the lowest possible frictional coefficient. The material combination
is usually dictated by the manufacturer of the modular link conveyor.

[0027]At the rear end, the modular link conveyor runs over a belt drive
shaft or roller. The modular link conveyor is thereby driven by
gearwheels which engage in the ribs on the underside of the modular link
conveyor. These gearwheels are part of the belt drive shaft or roller at
the rear end of the platform.

[0028]The modular link conveyor can likewise be deflected at the front end
by such a shaft or roller or can also be directed around a
freely-rotatable rod. For a modular link conveyor with a pitch of 12.7
mm, a rod having a diameter of 19 mm will suffice to effect the
deflection. For a modular link conveyor of 10 mm thickness, the gradient
at the rear end of the platform will thus only measure 39 mm in height.

[0029]A wedge can be disposed in front of the freely-rotatable rod around
which the modular link conveyor is directed at the front end to bridge
the remaining gradient. The wedge concurrently constitutes protection for
the area. It can be formed from a bent steel plate, for example.

[0030]Instead of the freely-rotating rod, a knife edge can also be
provided around which the modular link conveyor is pulled. Although
greater friction occurs in this case versus deflecting around a
freely-rotating rod. In order to obtain an interlocking drive for the
circulating belt with the gearwheels via the belt drive shaft or roller
arranged at the rear area of the platform, the circulating belt needs to
be slightly taut.

[0031]The belt drive can be effected by a motor integrated into the
platform. Preferably, however, the belt drive is also integrated into the
transport vehicle. The transfer of the drive power from the transport
vehicle to the coupled platform is functionally provided by a gearwheel
on the transport vehicle meshing with a gearwheel on the platform when
the platform is coupled to the transport vehicle.

[0032]The platform-side gearwheel of the belt drive is situated either
directly on the belt drive shaft or on its own intermediate shaft located
below the belt drive shaft, whereby the actual belt drive shaft is then
driven by a lateral pair of gears in the supporting bars. If the
platform-side gearwheel is situated on the belt drive shaft, the
circulating belt needs to be interrupted at this point. This interruption
is not necessary when the platform-side gearwheel is situated on its own
intermediate shaft.

[0033]Depending on the width of the platform, the roll-off base or the
circulating belt comprises one or a plurality of adjacent modular belts.
The circulating belt stretches out in operation and therefore the
distance between the front deflection mechanism (roller, cylinder, rod or
knife edge) and the rear deflection mechanism (belt drive shaft or
roller) needs to be adjusted. To this end, a base inserted in the
platform frame is spilt lengthwise, perpendicular to the belt's direction
of conveyance. An eccentric or a splined strip is inserted into the
base's hollow space. Eccentrics or splined strips can be manipulated from
the outside. The base can thereby be stretched somewhat and the belt thus
adjusted.

[0034]The transport vehicle preferably comprises one or a plurality of
steerable drive rollers and one or a plurality of free-wheel supporting
wheels which can alternatively function as freely-moveable steering
rollers or can be locked in the straight-ahead position. In the simplest
case, the transport vehicle has two front supporting wheels and a rear,
steerable drive wheel. The two front supporting wheels are functionally
configured as steering rollers which can preferably be fixed. When the
transport vehicle is coupled to the platform, the front steering rollers
will thus pivotably position the transport vehicle so that the steering
geometry is formed by the chassis at the front end of the platform and
the rear drive and steering wheel of the transport vehicle. On the other
hand, when the transport vehicle is uncoupled from the platform to drive
by itself, its two front steering rollers will be aligned and fixed with
the wheel axle perpendicular to the longitudinal axis of the transport
vehicle. The transport vehicle can then be driven like any standard
industrial truck.

[0035]To couple the platform to the vehicle, the vehicle engages by means
of centering bars in the corresponding recesses for the centering bars
configured on the platform. The centering bars are configured such that
the platform is in horizontal and vertical alignment when raised. To this
end, the centering bars of the transport vehicle can be designed to be
vertically adjustable. The vertical adjustment can be effected by
hydraulic cylinders or a spindle drive.

[0036]Two lateral hook ties are provided on the transport vehicle which
engage in the corresponding retaining brackets on the platform. The hooks
can be pulled back via hydraulic cylinders or spindle drives so that the
platform is braced against the transport vehicle. After the raising and
centering of the centering bars at the interface with the transport
vehicle, the platform has to be pressed and held against same. The
vehicle-side and platform-side drive gearwheel of the belt drive thereby
engage. During this process, the vehicle-side gearwheel is kept in
rotation in order to ensure the interlocking of the gearwheels.

[0037]In the coupled state of the transport vehicle and platform, a
hinging movement is preferably also possible about a horizontal axis.
This can be realized, for example, in that the centering bars taper
vertically to the tip or the centering bar receiving elements are
correspondingly widened so that while the centering bars are fixed at the
rear end of the platform, their tips nevertheless have vertical play.
Another possibility would be configuring the centering bars to be
pivotable, whereby they are pretensioned in a somewhat horizontal beating
so that they make contact with the receiving elements at the rear end of
the platform upon coupling. The vehicle-side gearwheel of the belt drive
is in this case moveable and pretensioned toward the platform such that
there is always engagement with the platform-side gearwheel in the
coupled state.

[0038]Another further possibility entails centralizing all the
vehicle-side mechanisms of the belt drive and the actuation of the
chassis in one function box which can be fixedly coupled to the rear end
of the platform and is articulated to be pivotable about a horizontal
axis and vertically displaceable on the transport vehicle.

[0039]Steering rollers can be provided at the rear end of the platform so
that the platform can also be moved manually or by any type of tractor if
need be. Extendable or pull-out supports can additionally be provided on
the four corners of the platform, in particular at the rear corners. This
allows the platform to be securely transported in the loading area of a
truck.

[0040]In order to be able to load a truck, for example, the platform needs
to be capable of millimeter-exact maneuvering. To this end, the transport
vehicle couples at the rear end of the platform and raises the back of
the platform; the platform is supported in the front by the chassis.
Since in so doing, the chassis of the platform and the rear drive and
steering wheel of the transport vehicle form the steering geometry of the
transport device, millimeter-exact maneuvering becomes possible. Since
the chassis of the platform is positioned as close to the front end as
possible, the front end of the platform basically does not swerve or sway
out when cornering. The horizontal articulation neutralizes any
unevenness of the driving surface between the platform chassis and the
transport vehicle chassis. The horizontal compensating joint can also be
achieved by a specific implementation of the centering bar.

[0041]Further options for the transport device are as follows:
[0042]Instead of a freely-movable transport vehicle, the platform is
coupled to a mechanically-controlled telescopic arm which moves the
platform and pushes it e.g. onto the loading area of a truck. [0043]As an
enhancement, a plurality of platforms are positioned behind one another
on a transport belt and transferred by means of a telescopic arm, whereby
an unloaded platform is first passed to a second conveyor belt beside it.
[0044]Permanent installation on the hydraulic lift of a truck having a
lowerable floor plate.

[0045]Reference will be made in the following to the drawings in
describing an embodiment of the invention in greater detail. Shown are:

[0046]FIG. 1: a top plan view of the platform with roll-off base;

[0047]FIG. 2: the platform of FIG. 1 as seen from the side;

[0048]FIG. 3: the front end of the platform of FIG. 1 as seen from below;

[0049]FIG. 4: a detail of a modular link conveyor in stereoscopic
depiction;

[0050]FIGS. 5, 6 and 7: the longitudinal adjustment of the platform to
tighten the circulating belt;

[0051]FIG. 8: a longitudinal bar having a mechanism to extend and retract
the chassis, whereby the chassis is extended;

[0052]FIG. 9: a longitudinal bar having a mechanism to extend and retract
the chassis, whereby the chassis is retracted;

[0053]FIG. 10: the function box and the rear area of the platform
diagonally from the front;

[0054]FIG. 11: the function box and the rear area of the platform
diagonally from the rear;

[0055]FIG. 12: an isometric representation of a further embodiment of the
transport device;

[0056]FIG. 13: an isometric detail representation of a coupling device for
the embodiment shown in FIG. 12;

[0057]FIG. 14: an isometric representation of the transport vehicle of the
embodiment shown in FIG. 11;

[0058]FIG. 15: an isometric detail representation of the coupling region
of the transport platform;

[0059]FIG. 16: an isometric representation of the belt drive of the
transport platform;

[0060]FIG. 17: an isometric representation of the transport device and its
belt drive device as seen diagonally from above;

[0061]FIG. 18: an isometric representation of the transport device and its
belt drive device as seen diagonally from below;

[0064]FIG. 20: a cross-section through the embodiment of the transport
platform according to FIG. 12.

[0065]FIGS. 1 and 2 show an embodiment of an inventive transport device
10. The transport device 10 is comprised of a platform 12 and a transport
vehicle 14. The platform 12 can be coupled to the transport vehicle 14.

[0066]The platform 12 has a flat, rectangular frame 16 with lateral
longitudinal bars 18 and crossbars. A retractable and extendable chassis
20 is provided at the front end of the frame 16. The chassis 20 can, as
FIG. 1 depicts, exhibit a tandem roller 22. The tandem roller 22 cannot
be steered. Given a lesser load on the platform 12, a chassis 20 can also
have a single roller or, at a particularly high loading, same can be
provided with an apron conveyor, as is presented in FIG. 2 as an
alternative.

[0067]Additional, steerable if need be, free-wheel rollers 24 can be
provided in the rear area of platform 12. The platform 12 can then be
moved with conventional tractors or also manually, thus independently of
the transport vehicle 14.

[0068]A modular link conveyor 26 which functions as a circulating belt and
rolling base, is guided on a closed circulating track in frame 16. The
modular link conveyor 26 essentially extends the entire length of the
platform 12. The modular link conveyor 26 is guided over a belt drive
shaft 28 at the rear end of platform 12. At the front end, it is guided
over a freely-rotatable deflecting rod, a similar deflecting roller 30,
or a knife edge. Sliding plates are positioned on the frame 16 on which
slides the upper strand of the modular link conveyor 26.

[0069]The transport vehicle 14 can be, for example, a standard industrial
truck equipped with lockable steering rollers 42--as will be described in
detail below--and with a hydraulic or electrical power train or another
suitable power supply. A function box 32 is mounted at the front of the
transport vehicle 14 which comprises the mechanisms necessary to couple
to the platform 12 in order to drive the circulating belt 26 or the
rolling base and extend and retract the chassis 20.

[0070]The individual components of the transport device 10 will be
described below in detail:

[0071]The modular link conveyor 26 is comprised of a plurality of chain
links 34 having a series of interspaced grommets 36 along the respective
front and rear edge (FIG. 4). The grommets 36 of one chain link 34 series
are offset relative the grommets 36 of the other series of the same chain
link 34, and the width of the grommets 36 is equal to their respective
spacing so that the one series of grommets of a chain link interconnects
with a series of grommets of the preceding or following chain link 34 and
can be connected by means of a connector pin 38 which is pushed through
the aligning grommets 36 of the preceding and following chain link 34.
The two series of grommets of each chain link 34 are connected by a
tangentially-arranged web of the grommets 36 so that the upper side of
the modular link conveyor 26 is even while the grommets 36 on the
underside form transverse ribs. The ribs engage with the sprockets of
belt drive shaft 28. The ribs also enable the modular link conveyor 26 to
slide along the sliding plate. The deflecting roller 30 at the front end
of the platform 12 is of cylindrical shape. The diameter of deflecting
roller 30 is as small as possible and corresponds approximately to the
pitch of the modular link conveyor 26. The height of the gradient at the
front end of the platform 12 can thereby be kept very low.

[0072]A belt drive 40 transfers the traveling motion of the transport
device 10 to the modular link conveyor 26 such that the upper strand of
the modular link conveyor 26 appears to be still and not moving relative
the ground surface. The belt drive 40 comprises a positional determining
device. One of the free-wheels or rollers 42 of the transport vehicle can
function, in conjunction with an angular rotation sensor, as a positional
determining device. The displacement signal of the angular rotation
sensor controls the belt drive 40 such that when the platform 12 is
pulled back, the modular link conveyor 26 is driven at the same speed in
the opposite direction of travel, whereby a load atop the modular link
conveyor 26 does not change its position relative the ground surface and
is ultimately set onto the ground over the front edge of the platform 12.

[0073]A drive mechanism 46 of the belt drive 40 is arranged for this
purpose inside the function box 32 and draws its operating power from an
electric motor supplied by a battery of the transport vehicle 14 or from
the hydraulic mechanism of the transport vehicle 14. The belt drive
exhibits a vehicle-side gearwheel 50 driven by the drive mechanism 46,
the periphery of which is partly exposed at the front end of the function
box 32. When the platform 12 is being coupled to the transport vehicle
14, this gearwheel engages with a platform-side gearwheel 52 at the rear
end of platform 12, whereby said gearwheel 52 is drive-connected to the
modular link conveyor 26. The platform-side gearwheel 52 of the belt
drive 40 is situated underneath the belt drive shaft 28 on an
intermediate shaft 44 which drives the belt drive shaft 28 by means of a
lateral pair of gearwheels 82 (FIG. 2).

[0074]The belts stretch out in operation and need to be able to be
adjusted from time to time. For this purpose, the base 48 positioned in
the platform frame 16 is split lengthwise, at right angles to the
conveying direction of the belt 26. An eccentric 56 (FIG. 5) or a splined
wedge strip 58 (FIGS. 6 and 7) is positioned in a hollow space 54 at the
location of the split of the profiled base. The eccentric 56 or splined
strip 58 can be manipulated from the outside. While the belt drive shaft
28 is fixedly mounted in the frame 16, the deflecting roller 30 is
mounted to the foremost element of the positioned base 48 and is moved
together with same. Turning the eccentric 56 or moving the
opposing-splined strip 58 results in some degree of stretching of the
positioned base 48 as a whole and thus retightening of the belt 26.

[0075]FIG. 7a shows an isometric representation of this length-variable
transport platform 12 in a diagonal view from above. Depicted is the base
48 which is split into two base sections 148 and 148'. The hollow
honeycomb structure to base 48 and a corresponding section cut forms a
hollow space 54 in this embodiment which serves to receive the splined
wedge strip 58. In accordance with the invention, this splined wedge
strip can now adjust the length of the transport platform 12, base 48
respectively, within a certain range and thus react to the change in
length of the transport belt (not shown). By virtue of the individual
opposing-splined components of wedge strip 58, their displacement in a
transverse direction RQ can change the distance between the two base
sections 148; 148' in longitudinal direction RL. It is to be noted
in conjunction hereto that it is possible to automate the above length
adjustment by means of appropriate regulating elements and appropriate
sensors so as to always ensure a required tension for belt 26. For
example, an eccentric can be equipped with a rotational position device
controlled by tension sensors on belt 26 so the eccentric can thereby be
turned back and forth based on the detected tension.

[0076]FIGS. 3, 8 and 9 show a longitudinal bar 18 in which the mechanism
for the retracting and extending of the chassis 20 is integrated. The
longitudinal bar 18 has a rectangular profile configured at its front end
as a U-profile open downward such that its underside is open to chassis
20. A double-arm angle lever 60 is mounted at the front area of the
longitudinal bar 18. The two angular arms 62 and 64 of angle lever 60
form an angle of approximately 80 degrees and the angle lever 60 is
mounted at the intersecting point of said two angular arms 62 and 64. The
forward-facing angular arm 62 is approximately two or three times longer
than the rearward-facing angular arm 64.

[0077]The tandem roller 22 is mounted at the free end of forward-facing
angular arm 62. The free end of the rearward-facing angular arm 64 is
articulated to a push/pull rod 66 which extends through a guide 68 to the
rear end of longitudinal bar 18. A pressure spring 70 is seated on the
push/pull rod 66 which is braced against the rear of guide 68 and a stop
72 on the push/pull rod 66 and thereby pretensions the push/pull rod 66
rearward so that the chassis 20 is normally extended (FIG. 8). Subjecting
the rear end of the push/pull rod 66 to a force which overcomes the
initial tension allows the chassis 20 to retract (FIG. 9).

[0078]FIGS. 10 and 11 show the rear end of platform 12 and, at a slight
distance therefrom, the function box 32. Two centering bars 74 extend
forward from function box 32. They are received in the corresponding
centering bar receiving elements 76 when coupling. The receiving element
76 of the centering bar and the centering bar 74 itself are mated to one
another with very little play. Hook ties 78 are further provided on the
sides of the function box 32 which engage with brackets 80 in the
recesses at the rear end of platform 12 such that the platform 12 is
fixedly coupled to the function box 32. The hook ties 78 are moved and
tensioned by hydraulic cylinders or spindle drives (not shown).

[0079]During the coupling process, the vehicle-side drive gearwheel 50 for
the circulating belt 26 and the platform-side gearwheel 52 engage. The
vehicle-side drive gearwheel 50 is held in rotation during the coupling
in order to ensure engagement of gear-wheels 50, 52. In the coupled
state, the vehicle-side gearwheel 50, mounted in the function box 32, and
the platform-side gearwheel 52 then engage. The platform-side gearwheel
52 sits on the intermediate shaft 44 (FIG. 2), its rotation transferring
to the belt drive shaft 28 via a lateral pair of gears 82. The
vehicle-side gearwheel 50 is driven by the drive mechanism 46 on the
vehicle 20 and thus drives the modular link conveyor 26 via this gear
train.

[0080]While the function box 32 is fixedly pressed to the platform 12 in
the coupled state, the function box 32 is articulated to transport
vehicle 14 (articulation 88) so as to still enable a limited tilting
motion about a horizontal axis and the transport device 10 consisting of
platform 12 and transport vehicle 14 can adjust to ground irregularities.

[0081]The function box 32 is secured to the transport vehicle 14 to be
height-adjustable. The height adjustment is realized by hydraulic
cylinders or a spindle drive. The maximum lift is relatively small and
only selves to lift the tear end of the platform 12 somewhat off the
ground in order for the platform to be able to travel.

[0082]Actuating cylinders 84 are further provided in the function box 32,
the pistons 86 of which engage in the rear ends of the push/pull rods 66
in the coupled state of vehicle 14 and platform 12. By the pistons 86 of
the actuating cylinder 84 subjecting the rear ends of the push/pull rods
66 to enough force, the initial tension of the push/pull rods 66 can be
overcome and the vehicle 20 retracted.

[0083]The inventive platform 12 serves to facilitate loading and to save
time in transporting and order picking. In loading, the front chassis 20
is extended and sets the platform 12 on the rear end of the frame 16 so
that the platform 12 is level. The platform 12 can be stocked by means of
forklifts, hoisting equipment or hand trucks in the usual way. Loading
can, of course, also be performed by a loading robot.

[0084]When the platform 12 is fully loaded and is to be driven e.g. onto
the loading area of a truck, the transport vehicle 14 couples to the
platform 12, lifts the rear end of the platform 12, and drives the
platform 12 onto the loading area of the truck. Whereby the chassis 20 is
naturally extended. The payload can be transported on the truck to the
intended destination together with the platform 12 or without the
platform.

[0085]In the first case, the transport vehicle 14 uncouples from the
platform 12 on the truck, which couples to another transport vehicle 14
at the intended destination, pulls the platform 12 from the truck, and
drives it for example to a predetermined location within the warehouse.
There, by means of the actuating cylinder 84, the chassis is retracted
and the front end of the platform 12 is thereby lowered to the ground.
The belt drive 40 is then activated and the platform 12 pulled back. The
belt drive 40 is thereby controlled by the positional determining device
so that the modular link conveyor 26 is driven at the exact same speed,
albeit in the opposite direction, whereby the platform 12 is pulled back
from the transport vehicle. The payload is thereby unloaded exactly at
its intended location.

[0086]In the second case, the platform 12 has already been pulled back
from the transport vehicle 14 by the truck's loading area. The platform
12 is hereto lowered and the belt drive 40 with the positional
determining device activated so that the payload on the truck's loading
area can be set down at the exact intended location.

[0087]The chassis 20 at the front end of the platform 12 and the rear
drive and steering wheel 90 of the transport vehicle 14 then form the
steering geometry of the transport device 10. What is distinctive,
however, is that the horizontal axis of the articulation 88 can
counterbalance irregularities in the driving surface between the chassis
20 of the platform 12 and the chassis 42, 90 of the transport vehicle 14.
The front free-wheel supporting wheels 42 of the transport vehicle are
thereby released so that they can function as freely-moving steering
rollers.

[0088]When the transport vehicle 14 is uncoupled from the platform 12, the
supporting wheels 42 are aligned and fixed such that their wheel axles
are perpendicular to the longitudinal axis of the transport vehicle 14.
The transport vehicle 14 can then be driven like any standard industrial
truck.

[0089]FIG. 12 shows an isometric representation of a further embodiment of
transport device 10. This configuration is shown in detail in FIG. 13
focussing on a coupling device 110.

[0090]Shown are a transport vehicle 14 and the transport platform 12
coupled thereto. The transport platform 12 here comprises three
parallel-extending belts 26 configured to circulate between a front end
102 and a rear end 104. To support the belts 26, the transport platform
12 exhibits a belt drive shaft 28 and a deflecting roller 30 which are
kept substantially parallel to one another in a frame 16. The belt drive
shaft 28 can, as will be described in greater detail below, be driven by
a corresponding vehicle-side belt drive device 120.

[0091]As with the preceding embodiment, the transport device 10 shown here
comprises an extendable chassis 20 (see FIGS. 15 and 18), arranged in the
area of the front end 102. At the rear end 104, the transport platform 12
can be coupled to the transport vehicle 14 by means of a coupling device
110. Said coupling device comprises a lifting frame 112 on which lifting
arms 114 are configured which can be brought into interacting connection
with the receiving pockets 116 on the transport platform 12 such that the
rear end 104 of the transport platform 12 can be lifted and lowered.

[0092]The coupling in this embodiment is moreover realized such that the
transport platform 12, pivotable about a horizontal axis relative the
transport vehicle 14, is fixedly coupled to the transport vehicle 14
about a vertical axis; i.e. an axis perpendicular to the transport
platform 12. After coupling, the transport vehicle 14 and the transport
platform 12 can be navigated as one unit, in particular by the lockable
steering wheels 42 arranged on transport vehicle 14.

[0093]The coupling device 110 comprises the above-cited lifting arms 114
arranged on the lifting frame 112 of transport vehicle 14. Pick-up
mandrels 118 extending congruently to the receiving pockets 116 on the
transport platform 12 are configured on the lifting arms 114. When
coupling the transport vehicle 14 to the transport platform 12, the
pick-up mandrels 118 slide into the receiving pockets 116 and lock when
the lifting arms 112 are raised so that the transport platform 12 is
securely coupled to the transport vehicle 14.

[0094]FIG. 14 shows the transport vehicle 14 schematically and in an
isometric representation. Identifiable here is the lifting frame 112,
constructed here to be substantially symmetrical, and comprising the
lifting arms 114, on which the essentially orthogonal forward-projecting
pick-up mandrels 116 are formed. Said forked lifting frame 112 with its
lifting arms 114 can be pivoted upward and downward via adjusting
mechanism 119 so as to raise and lower, respectively couple and uncouple,
the transport platform 12 (see FIG. 13).

[0095]In FIGS. 15 and 16, a section, individual components respectively,
of the transport platform 12 have been cut out and illustrated in detail;
specifically of an end plate 122 positioned at the rear end 104 of the
transport platform (see FIG. 17). The end plate 122 in this embodiment
exhibits two center openings 124 which serve the lateral centering of the
transport platform relative the transport vehicle 14 when coupling. When
connecting the transport platform 12 to the transport vehicle 14, the
vehicle-side pick-up mandrels 118 (see FIG. 14) engage through the center
openings 124 in order to lock in place with the platform-side receiving
pockets 116. Due to the geometric configuration of the center openings
124 here, in particular the pitched lateral edges 126, the pick-up
mandrels 118 (see FIG. 14) are guided to fit precisely into the receiving
pockets 116 of the transport platform.

[0096]A drive opening 128 is further depicted on the end plate 122,
offering access to a platform-side gearwheel 52 and associated drive
system for the transport platform and in particular for the chassis 20 of
transport platform 12. This detail will be addressed in more specific
terms below.

[0097]FIG. 15 schematically depicts hereto the chassis construction of the
transport platform 12. It encompasses two chassis 20, each comprising a
tandem roller 22, which are retractable and extendable by means of
push/pull rods 66. The push/pull rods 66 have pressure springs 70 for
this purpose which are pretensioned against a guide 68 and a stop 72 so
that the chassis 20 is retracted. By means of an ejector 130 likewise
accessible through the end plate 122, the initial tension applied by the
pressure spring 70 can be overcome and the chassis 20 extended. In
conjunction hereto, reference is expressly made to the above-described
embodiment and the respective procedure for retracting and extending the
chassis; same also applies here.

[0098]FIG. 16 now shows the representation of FIG. 15 from the rear and
likewise in a schematic isometric depiction. The end plate 122 is
depicted here as well, arranged on the rear end 104 of transport platform
12. The end plate 122 covers the platform-side belt drive device 132
serving to drive the belts 26 (see FIG. 12).

[0099]Illustrated hereto is an intermediate shaft 44 comprising the
platform-side gearwheel 52 by means of which the platform-side belt drive
device 132 is driven by the transport vehicle 14. By means of the lateral
pair of gears 82, the drive force of the transport vehicle 14 is also
transferred here from the intermediate shaft 44 to the belt drive shaft
28 which drives belt 26 (see FIG. 12). Relevant hereto is that the
rotational axis of the intermediate shaft 44 runs coaxially to the
central axis AM of the receiving pockets 116.

[0100]FIG. 17 now again shows the embodiment from FIG. 12 in an isometric
representation, whereby special attention is focussed here on the
vehicle-side belt drive device 120. This vehicle-side belt drive device
120 is substantially comparable to the function box 32 described above
(see FIGS. 10 and 11); it is likewise arranged to be pivotable on
transport vehicle 14 and here within the lifting frame 112. By pivoting
about a substantially horizontal axis; i.e. here an axis parallel to the
transport platform 12, the vehicle-side belt drive device 120 and a
vehicle-side drive wheel 50 arranged thereon can be pivoted into the
drive opening 128 of the end plate 122 so that the vehicle-side drive
wheel 50 operatively interacts with the platform-side drive gearwheel 82.

[0101]The functioning of this drive device, the vehicle-side drive device
120 and the platform-side belt drive device 132 respectively, is depicted
in greater detail in FIG. 18. Identifiable are the two gearwheels 50; 82
which operatively interact upon the pivoting of the vehicle-side belt
drive device 120 so that the rotational forces are transferred to the
intermediate shaft 44 and from there via the lateral gear pair 82 to the
belt drive shaft 28 and from there to belt 26.

[0102]The above embodiment of the transport platform 12 is depicted in a
side view in FIG. 20. Again identifiable is the frame 16 comprising both
the deflecting roller 30 at front end 102 as well as the belt drive shaft
28 and the intermediate shaft 44 at rear end 104.

[0103]Again depicted are the two transverse connectors 134 and 136 which
offer the inventive transport platform 12 both reinforcement from a
structural standpoint as well as the seating ability for a conventional
forklift to, for example, pick up the transport platform 12 in a
transverse direction and transport same.

[0104]Moreover recognizable in FIG. 19 is the chassis 20 of the transport
platform 12. It comprises in known manner the tandem rollers 22 which are
connected to the trans-port platform 12 via an angle lever 60. The
chassis 20 can be extended and retracted by means of a push/pull rod 66
pretensioned by a pressure spring 70. The ejector 130 is provided for the
extending; it runs through the end plate 122 and can be activated for
example by means of a corresponding hydraulic actuator on transport
vehicle 14 (not shown).